This invention relates generally to a device to replace the time-honored common hook, the spliced-end loop, and the conventional knots used on tow ropes and hoist ropes of all kinds used for towing and lifting loads of all kinds.
The common open hook long has had several drawbacks and has caused certain inconveniences and annoyances. Now with the advent of newer ropes with more elasticity, the stress on ropes can be increased immensely resulting in even more danger of breaking hooks. Those broken hooks have resulted in high speed backlash which sends ropes with broken hooks in the opposite direction in a highly dangerous fashion, many times in the death or serious injury to persons, and also to property damage.
Furthermore, the common hook also has been the cause of inconvenience and annoyance because it easily unhooks itself with alternating tensioning and slackening of load pressures.
Also, conventional knots in stretchable rope tend to get impossibly tight when under pressure because the rope narrows in diameter. Ropes tied with this kind of pressure cannot be untied and must be cut.
Still another advantage of the steel knot is that it can be slid off the rope easily when the rope is used without a hook. Reattaching the steel knot is just a matter of rethreading it.
The steel knot is neither a conventional knot nor a hook, but it replaces both. The steel knot has advantages over the conventional rope in other ways. While the term "steel knot" is used because most adaptations will be of steel, it is not required that this invention be manufactured of steel. In some instances plastics will serve well.
Earlier inventors have designed metal or otherwise rigid fasteners for rope, string, wire, and cord but no known fastener performs all the necessary functions of the present invention.
D. Gould (U.S. Pat. No. 1,053,593) discloses a cord adjuster for electrical cord. However, the Gould device would function poorly as a steel knot because it features half loops and not rings on the ends. Also the three bars are not parallel to each other and they are approximately evenly spaced which would inhibit use of ropes of differing diameters. Furthermore, under extreme pressure Gould's device would tend to compress when absolute rigidity is necessary.
A. E. Davis (U.S. Pat. No. 535,680) discloses a shoe lace tie fastener. It consists of a hollow member which is split lengthwise through its walls at 180 degrees to each other. The sides of the member are expanded to allow passage of a shoe lace. A larger version of the Davis device would not work well as a steel knot because it would have sharp "V" edges at the ends of the slits which would create cutting edges and would damage rope. Also, one method of tying rope with a steel knot requires an overhand knot on the end. This kind of knot would be pulled into the "V" slits of the Davis invention and would be damaged.
H. E. Forman (U.S. Pat. No. 1,718,641) discloses a metal fastener for rope which consists of two half-loops and two bar connectors held to the rope with a cotter pin. Forman's fastener will lend itself to one kind of knot, but would not work well when tied as indicated by FIG. 3 of the present invention. The open clamps of the Forman device either would bend under pressure, or else the device would have to be constructed of unnecessarily heavy materials to work with present-day nylon ropes. Also, the cotter pin would damage the rope.
J. C. Casanave (U.S. Pat. No. 3,094,755) discloses a rope and connector assembly which is compressed of two parallel metal barrels welded together. The Casanave device varies from the steel knot in several ways. This device requires an overhand knot permanently tied in the end of the rope. The device requires a tethering post. It is limited in the size of rope it will accept. It cannot be tied as indicated by FIG. 3 of the present invention. It cannot be removed from the rope without cutting the knot when the assembly is not to be used.
Paul T. Beggins (U.S. Pat. No. 4,414,712) discloses a double barrel line fastening device. This device threads the rope in such a way as to force it into outward bends for retention. Such bends work well for tethering but would not work as well when the goal is safety as in tow ropes. They would not snap free as readily as would the present invention. The Begins device is also limited as to the sizes of ropes the device would accommodate.